Global coupling at 660 km is proposed to explain plate tectonics and the generation of the earth's magnetic field

TL;DR

This paper proposes that a low-viscosity layer at 660 km depth facilitates differential rotation, explaining plate tectonics and Earth's magnetic field generation, supported by geological, geophysical, and dynamo modeling evidence.

Contribution

It introduces a global coupling model at 660 km depth that accounts for plate tectonics and magnetic field generation, integrating geological observations with dynamo theory.

Findings

Low viscosity at 660 km enables differential rotation.

The dynamo model reproduces features of Earth's magnetic field.

Model aligns with geological and geophysical data.

Abstract

The presence of low viscosity layers in the mantle is supported by line of geological and geophysical observations. Recent high pressure and temperature investigations indicated that partial carbonate melt should exist at the bottom of the lithosphere and at 660 km. The presence of few percent carbonate melt reduces the viscosity by several order of magnitude. The globally existing 660 km very low viscosity layer allows the development of differential rotation between the upper and lower mantle. This differential rotation between the 660 km outer shell and the rest of the earth offers a plausible explanation for plate tectonics and for the generation of the earth's magnetic field. Simple dynamo model is proposed, which able to reproduce all of the features of the contemporary and, within reasonable uncertainty, the paleomagnetic field. The model is also consistent with geological and geophysical observations.